"The Revenge of the Bat," a free lecture on "Die Fledermaus," will take place at the Peterson Library, 9340 S. Seventh East, on Thursday at 7:30 p.m.

Utah Opera's music director, Byron Dean Ryan, and Dr. Krista Rodin will speak about the composer (Johann Strauss), the opera, and its historical setting in 1870 Vienna, assisted by sopranos Susan Deauvono and Tricia Swanson, who will sing arias from the opera."Die Fledermaus" is scheduled for Utah Opera production at the Capitol Theater May 11, 13, 15 and 18 at 8 p.m., and May 21 at 2 p.m.